Multiply paper sheet



June 1932- C. DE L. WOOD, SR

MULTIPLY PAPER SHEETS Filed Sept. 29, 1959 IN VENTOR.

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ATTORNEY.

atented dune 2T, 1932 H l: LES DE LORMAN WOOD, SR., OF LAKEWOOD, OHIO,ASSIGNOR TO E GRASSELIIL CHEMICAL COMPANY, 015' CLEVELAND, OHIO, ACORPORATION OF DMAWARJE MuL'rrrLY earns. smear Application filedSeptember 29, 1930. Serial No. 485,300.

My invention is directed to multiply paper sheets useful in themanufacture of containers, for insulating or other purposes wherein ahigh grade, strong multiply sheetis desired, and it comprises multiply'paper, or board, in which sheets of diflerent COIISHLIC- tion arecombined. I

By construction of the paper I refer to the method or tiype of papermachine used to produce it. W0 main types of construction of paper areknown.

Tn the'older, cylinder machines, a paper is produced in which theindividual. fibres are laid substantially in one direction only,parallel to the run of' the sheet, resulting in a product which has adifferent strength in various directions and by a tearing test one caneasily distinguish a paper made on a cylinder machine.

The operation of a cylinder machine involves super-imposing severallayers, usually up to 6, of pulp stock, which blend into a single sheetor board; each layer may have incorporated in it different sizes andpulp stocks, etc., but in all layers the fibres will.

have substantially the same direction. Any desired thickness of paper orboard, practically up to 0.08" oreven more, can be made directly on 'acylinder machine.

The other type of paper differing in construction from cylinder paper isobtained in what is known as a Fourdrinier paper forming machine. Thefibres in the Fourdrinier paper lay in all possible directions, wherebya paper of uniform strength is obtained. The

thickness of a paper which can be made on a Fourdrinier machine ispractically limited by t'ie speed at-which such a machine can be runeconomically. and it seldom exceeds 0.018". Another distinguishingfeature of the Fourdrinier paper is that any size or waterproofing agentadded to the paper stock will be distributed equally and uniformlythroughout the whole mass of the paper.

In the practice of my invention I combine one or more cylinder sheetswith one' or more Fourdrinler paper sheets, preferably alternating thetwo types of paper in laye s and joining the different plies by gluingthem together with sodium silicate or other adhesive. The attachedfigure represents in-its simplest form applicants multiply paper sheet.

A. is a sheet of cylinder paper, B a sheet of Fourdrinier paper, 0 showsthe adhesive which binds the two. A. corner of the oylinder paper sheetis shownbroken away to better illustrate the texture of the Fourdriniersheet. The shading in the figure is intended to show the construction ofthe sheets, namely, that in the cylinder paper the individual fibres laysubstantially all in one direction, whereas the fibres in. theFourdrinier sheet, as seen on its surface and seen in profile, lay inall possible directions. The drawing represents the sheets greatlyenlarged.

Multiply sheets consisting of alternating plies of cylinder andFourdrinier paper can be produced in any desired thickness. They willshow a considerable improved strength over similar sheets made fromcylinder pa er I only. I believe this to be due to the fact that thecellulose fibres are distributed in the different sheets in differentdirections.

I am, of course, not limitedto multiply sheets consisting of onecylinder and one Fourdrinier sheet glued together, but I can use anynumber of such sheets.

My invention also provides for the possibility of sheets which havesurfaces of different properties. One face of the sheetcan be of softabsorbent cylinder paper and the other side of a strong, hard sized,water resistant F ourdrinier sheet. Such sheets are particularly usefulfor making certain kinds of containers where the inside is treated tomake it grease proof.

In another embodiment of my invention I produce a multiply sheet inwhich both surfaces consist of hard sized, water resistant Fourdrinierpaper, withone or more soft, absorbent cylinder papers in between.

In the preferred embodiment of my invention I use unsized or onlyslightly sized cate of soda or other adhesive used, thereby roducing onthe surface of the sheet a more concentrated adhesive and a quickinitial set; furthermore, the absorbent cylinder sheet will continueexhausting the water from the adhesive until complete bond is obtained.Due to the strongly absorbent properties of the cylinder sheet the waterof the adhesive will be preferentially absorbed by the cylinder sheetinstead of by the hard sized, or water resistant Fourdrinier sheet,thereby substantially preventing migration of the water into the latterand preventing the attack of the sizing material contained therein.

-Multiply paper of my invention can be made on the machines commonlyused for building up multiply paper and board, and their method ofproduction differs from present practice only by the use of sheets ofpaper or board of different construction.

I cla1m:

1. A multiply paper sheet consisting of alternating plies of cylinderand Fourdrinier paper joined together by an adhesive.

2. A multiply paper sheet consisting of alternating plies ofsubstantially unsized,

absorbent cylinder paper and hard sized,

water resistant Fourdrinier paper joined together with an adhesive.

3. A multiply paper sheet consisting of alternating plies of cylinderpaper and hard sized, water resistant Fourdrinierpaper joined togetherwith a sodium silicate adhesive.

4. A multiply paper sheet consisting of a substantially unsized,absorbent cylinder paper joined with a sodium silicate adhesive to ahard sized, water resistant Fourdrinier sheet.

5. A multiply paper sheet consisting of a substantial y unsized,absorbent cylinder paper lined on each face by a hard sized, waterresistant Fourdrinier sheet, the plies beingjoined together with asodium silicate adhesive.

In testimony whereof, I aflix my signature.

CHARLES DE LORMAN WOOD, Sr.

